2025 ISAKOS Biennial Congress ePoster
Mid To Long-Term Results Of Medial Unicompartmental Knee Arthroplasty : Mobile Versus Fixed-Bearing
Sumin Lim, MD, Gyeonggi-Do KOREA, REPUBLIC OF
Jun-Young Chung, MD, Suwon, Gyeonggi-do KOREA, REPUBLIC OF
Tae Hun Kim, MD, Suwon, Kyounggi-do KOREA, REPUBLIC OF
Jeong-Hyun Koh, MD, Suwon, Gyeonggi-do KOREA, REPUBLIC OF
Jeong Sunwoo, MD, Suwon, Gyeonggi-do KOREA, REPUBLIC OF
Myung-Sub Lee, MD, Suwon, Gyeonggi-do KOREA, REPUBLIC OF
Ajou university hospital, Suwon, Gyeonggi-do, KOREA, REPUBLIC OF
FDA Status Not Applicable
Summary
When observing the mid to long-term results, there were no significant differences in WOMAC score, ROM, or radiological outcomes between mobile and fixed-bearing UKA. However, in terms of failure and survivorship, fixed-bearing UKA showed better results than mobile-bearing UKA.
ePosters will be available shortly before Congress
Abstract
Purpose
The purpose of the study was to analyze the mid to long-term results of medial unicompartmental knee arthroplasty (UKA) regarding bearing modality.
Methods
We retrospectively analyzed 81 consecutive UKA patients during the period when both fixed bearing and mobile-bearing were used for medial UKA. A total of 45 patients with fixed-bearing UKA and 36 with mobile-bearing UKA were included, all of whom had been followed up for more than 5 years. Clinical outcomes were assessed using Western Ontario McMaster Universities Osteoarthritis Index (WOMAC) score and knee range of motion (ROM). Radiologic parameters with Hip-knee-ankle axis angle (HKA) and osteoarthritis (OA) grade using Kellgren-Lawrence grading system were evaluated. Implant survivorship was assessed using Kaplan-Meier survival analysis.
Results
Demographic data did not differ between the fixed-bearing and mobile-bearing groups, with an average follow-up period of 127 months. There were no statistical differences between the two groups in terms of ROM, WOMAC score, contralateral OA progression, patellofemoral OA progression, and HKA. The mobile-bearing group had a statistically higher failure rate, both when considering failure as conversion only and when considering failure as conversion or polyethylene change. The mobile-bearing group had a statistically higher failure rate, both for conversion only (p=0.041) and for conversion or polyethylene change (p=0.009). 10-year survivorship was 97.8% for the fixed-bearing group and 88.3% for the mobile-bearing group, without a significant difference (p=0.066), when considering failure as conversion only. When considering failure as conversion or polyethylene change, 10-year survivorship was 97.8% for the fixed-bearing group and 83.3% for the mobile-bearing group, with a significant difference (p=0.015).
Conclusion
When observing the mid to long-term results, there were no significant differences in WOMAC score, ROM, or radiological outcomes between mobile and fixed-bearing UKA. However, in terms of failure and survivorship, fixed-bearing UKA showed better results than mobile-bearing UKA.